Fleet of Worlds

  Praise for Fleet of Worlds

  “A far-future SF mystery/adventure set two centuries before the discovery of the Ringworld by humans . . . Intriguing human and alien characters and lucid scientific detail.”

  —Library Journal

  “A new Known Space book, particularly one with new information about Puppeteers and their doings behind the scenes of human history, needs recommending within the science fiction community about as much as a new Harry Potter novel does—well, anywhere. But Niven and Lerner have produced a novel that can stand on its own, as well as part of the Known Space franchise.”

  —Locus

  “If you’re a Niven fan, just go buy the book. It’s that good! . . . It’s the finest Known Space work in many, many years that I’ve had the pleasure to read. This is an essential read for anyone interested in how good science fiction can be.”

  —The Green Man Review

  “A very worthy addition to the ongoing Known Space future history.”

  —Sci Fi Weekly

  “As we have long expected from Niven, it’s a great read, and Lerner—as Analog readers know—has the knack as well. You’ll enjoy this one.”

  —Analog Science Fiction and Fact

  “Larry Niven and Edward M. Lerner have teamed up to write the prequel [to Ringworld], and it’s well worth reading whether you’ve read Ringworld and its subsequent books or not.”

  —SFRevu

  “If a little knowledge is a dangerous thing, a lot of knowledge can rock worlds.”

  —The Kansas City Star

  TOR BOOKS BY LARRY NIVEN

  AND EDWARD M. LERNER

  Fleet of Worlds

  Juggler of Worlds

  TOR BOOKS BY LARRY NIVEN

  N-Space

  Playgrounds of the Mind

  Destiny’s Road

  Rainbow Mars

  Scatterbrain

  The Draco Tavern

  Ringworld’s Children

  WITH STEVEN BARNES

  Achilles’ Choice

  The Descent of Anansi

  Saturn’s Race

  WITH JERRY POURNELLE AND STEVEN BARNES

  The Legacy of Heorot

  Beowulf’s Children

  WITH BRENDA COOPER

  Building Harlequin’s Moon

  TOR BOOKS BY EDWARD M. LERNER

  Fools’ Experiments

  The author and publisher have provided this e-book to you without Digital Rights Management software (DRM) applied so that you can enjoy reading it on your personal devices. This e-book is for your personal use only. You may not print or post this e-book, or make this e-book publicly available in any way. You may not copy, reproduce or upload this e-book, other than to read it on one of your personal devices.

  Copyright infringement is against the law. If you believe the copy of this e-book you are reading infringes on the author’s copyright, please notify the publisher at: us.macmillanusa.com/piracy.

  This is a work of fiction. All the characters, organizations, and events portrayed in this novel are either products of the authors’ imagination or are used fictitiously.

  FLEET OF WORLDS

  Copyright © 2007 by Larry Niven and Edward M. Lerner All rights reserved.

  A Tor Book

  Published by Tom Doherty Associates, LLC

  175 Fifth Avenue

  New York, NY 10010

  www.tor-forge.com

  Tor® is a registered trademark of Tom Doherty Associates, LLC.

  ISBN-13: 978-0-7653-5783-0

  ISBN-10: 0-7653-5783-6

  First Edition: October 2007

  First Mass Market Edition: September 2008

  Printed in the United States of America

  0 9 8 7 6 5 4 3 2 1

  DRAMATIS PERSONAE

  HUMANS / CREW OF LONG PASS

  Diego MacMillan Navigator

  Jaime MacMillan Doctor

  Sayeed Malloum Engineer

  Barbara Nguyen Captain

  SOL-SYSTEM HUMANS

  Sigmund Ausfaller Amalgamated Regional Militia (ARM) investigator

  Sangeeta Kudrin Senior executive at the United Nations

  Julian Forward Physicist (native of Jinx, in the Sirius system)

  Miguel Sullivan Racketeer

  Ashley Klein Racketeer

  CONCORDANCE COLONISTS / CREW

  OF EXPLORER

  Kirsten Quinn-Kovacs Navigator and a math whiz

  Omar Tanaka-Singh Captain

  Eric Huang-Mbeke Engineer

  CONCORDANCE COLONISTS / OFFICIALS OF THE

  ARCADIA SELF-GOVERNANCE COUNCIL

  Sven Hebert-Draskovics Colonial archivist

  Sabrina Gomez-Vanderhoff Governor

  Aaron Tremonti-Lewis Minister, Public Safety

  Lacey Chung-Philips Minister, Economics

  CONCORDANCE CITIZENS

  Nessus Political officer on Explorer; Experimentalist neophyte

  Nike Deputy Minister, Foreign Affairs; Experimentalist radical

  Eos Leader of out-of-power Experimentalist Party

  Hindmost / Sisyphus Leader of the government and the Conservative Party

  Baedeker Engineer at General Products Corporation

  Vesta Nike’s senior aide

  FLEET OF WORLDS TIMELINE

  (All dates in Earth-standard)

  2095

  Ice World begins its interstellar journey.

  2197

  Long Pass signals to the Ice World, spotted one light-year away.

  2198

  Long Pass is boarded.

  2645

  A supernovae chain reaction is discovered at the galaxy’s core.

  The Fleet of Worlds begins its flight to safety.

  2650

  First expedition of Explorer to the Gw’oth world.

  In Known Space, UN authorities renew their search for the recently vanished Puppeteers.

  Political crises brew on Earth and Hearth.

  Colonists seek the truth about their past.

  And so: Many events, on several worlds, ensue.

  2652

  New Terra charts its own course.

  PROLOGUE

  Earth date: 2197

  Long Pass crossed the sky in a series of shallow curves, because Diego MacMillan willed it so.

  Interstellar space is not uniform. The tenuous interstellar medium isn’t just a few atoms of hydrogen per cubic inch, forever. There are pockets of greater density, some thick enough to form strings of stars, given time. Between the dense patches there is nothing. A Bussard ramjet like Long Pass, which eats interstellar hydrogen and accelerates by spitting out fused helium, must coast between the denser clouds.

  This is worse than it sounds. At any reasonable fraction of light speed, interstellar muck comes on like cosmic rays. As much as propulsion, a Bussard ramjet’s purpose is to guide that lethal muck away from the life support system.

  Every simulation run in Sol system had reached the same inconclusive conclusion: Course tweaking to exploit density fluctuations in the interstellar medium was “likely to be” unproductive. Between Sol and the target star the muck was thick enough. Sure, a course tweak might funnel a bit more hydrogen into the ramscoop here, but was it enough to compensate later? A slight diversion at these velocities took a heavy toll in kinetic energy. And what would you find when you reached the end of a detour? Maybe that was where the law of averages caught up with you, and the near-vacuum of interstellar gas became vacuum indeed.

  Of course, flatlanders had built the models. Diego MacMillan had nodded noncommittally at their advice. Technically he was also a flatlander—spacers pinned that label on every Earthborn—but he had traveled across the solar system. Once Long Pass launched, whether he undertook the experiment was beyond their control. br />
  The question had never before come up on a manned mission. Long Pass was experimental, a crew-rated ramscoop.

  In the abstract, Diego respected the mission planners’ conservatism. The ship’s failure could discredit the new technology for a long time.

  Flatlanders! He and his wife were aboard. That was more than enough to keep him from taking foolish chances.

  So Long Pass had followed its wobbly curves for decades now. Maybe he’d saved a few months’ travel. That was okay. Studying the variations, plotting alternate courses, assessing probabilities—they kept him busy. What had the experts imagined the ship’s navigator would do for decades?

  They could never have imagined what, in his obsessive peering ahead, he would find.

  AND TO WHAT do we owe this honor?” Captain Nguyen asked.

  Meaning that by the current schedule Diego would normally be asleep. It was all he could do not to blurt out the answer. One step at a time, he told himself. “All will be revealed,” he intoned with his best mock pretension.

  The ship’s population numbered just above ten thousand. Most were embryos, sharing the freezers with forty-three hibernating adult passengers. The crew numbered only four, between them covering three daily shifts. Together, they filled the ship’s tiny dayroom.

  He had arrived early to configure the claustrophobia-denying decor. Undulating, verdant forest, the Andean foothills of his youth, receded into the digital wallpaper. Fluffy clouds scudded across the brilliant blue sky glowing overhead—he had no use for the cave-parks his Belter crewmates thought normal. Leaves rustled and insects droned softly in surround sound. Most of one wall presented a well-remembered mountain lake on which a sleek, two-toned power boat cruised. Its hundred-horsepower inboard motor was throttled down to a barely audible purr.

  Nothing, alas, could mask the ubiquitous odor of endlessly recycled air, nor could the rough-hewn planks projected from the dayroom table disguise the plasteel slickness beneath his fingers. He twiddled the cabin controls, tuning chirps and twitters down a notch, while his curious shipmates took coffee and snacks from the synthesizer.

  Barbara Nguyen sat first. She had the tall, gangly frame of a Belter, and her head was shaved except for a cockatoo-like Belter crest of thick black hair. She was their captain and the most cautious among them; which was cause and which effect remained stubbornly unclear to Diego. Throughout their hitherto uneventful voyage, she had let decisions emerge by consensus. With luck, consensus-seeking had become a habit.

  Sayeed Malloum, their engineer, was taller still but stocky for a Belter. Each of them handled the tedium in his own way. Sayeed’s latest affectation, dating back several weeks, involved dyeing his crest and disposable jumpsuit in matching colors. Today’s hue was chartreuse, shading to deep yellow.

  Jaime MacMillan, ship’s doctor and Diego’s wife of fifty years, slid into the last chair. She was built to earthly scale, nearly matching his six feet, but otherwise illustrated the old adage about opposites attracting. She was lithe while he was pot-bellied, blonde where he was dark, and as fair as he was swarthy. Those were shipboard skin tones, of course. Flatlander full-body dye jobs and elaborate skin patterns had been left on far-off Earth.

  Jaime slipped a hand beneath the tabletop to give his knee a reassuring pat, although not even she knew what he was about to reveal. With a start, he noticed she had printed her jumpsuit in Clan MacMillan tartan: another silent vote of confidence. How anxious did he seem?

  Barbara cleared her throat. “Spill it, Diego. Why did you call everyone together?”

  Oh, how the details and analyses, all the terabytes of specifics in his personal journal, yearned to be free. This was not the time. “Have a look.” Above the picnic-table illusion he projected a navigational holo. Amid the scattered pink, orange-white, and yellow-white specks of the nearest stars, a brilliant green asterisk blinked: You are here. As his friends nodded recognition, he superimposed, in tints of faint gray, a delicate 3-D structure. Would they see it? “Density variations in the interstellar gas and dust.”

  Sayeed frowned, likely anticipating another pitch for rerouting the ship on one more just-a-bit-off-our-planned-course wrinkle in the void.

  “You’ve shared density plots before. It’s never involved much fanfare.” Barbara eyed him shrewdly. “And you’ve never before struggled so hard not to bounce in your chair.”

  Words alone would not suffice—not for this, not with Belters. That was not a criticism. Growing up inside little rocks, they lacked the background. Diego said, “Jeeves, give us Boat One.”

  “On full throttle, sir, as you had specified.” The virtual speedboat slewed until its stern faced them and the shore. With a roar, the boat’s bow rose. A great vee-shaped wake formed. Diego tracked the boat as it receded, the ripples of its wake dwindling as they spread.

  Sayeed’s gaze flicked between the simulated lake and the 3-D graphic that still hung above the table. “There’s a shock wave in the interstellar gas. A . . . a bow wave.”

  Barbara narrowed her eyes in concentration. “I concede the resemblance, but we’re comparing two simulations. Diego, are you certain about the underlying data?”

  It would be so easy to dive into minutiae about years of observations patiently culled and collated, about converting those observations from the ship’s accelerating frame of reference to a stationary frame, about estimating and correcting for the perturbations of stellar winds. He could have discussed at length vain efforts to match his readings to the sky survey with which they had departed Sol system. He yearned to explain the extrapolation of the full pattern from the mere fraction so far glimpsed, even after so many years and light-years of observations.

  He must have had a fanatical glint in his eye, because Jaime shot him the warning look that reminded: There’s a fine line between scary-smart and just scary. Diego kept his response to a confident nod.

  Barbara said, “I’ll want to go through it later, step by step. No offense, just captain’s prerogative.”

  “What could have made this bow wave?” Sayeed asked.

  That was the right question. Diego started another simulation. A more nearly uniform background wash, modeled from a century-old survey, replaced the translucent ripples in the stellar display. “This is what we expected to encounter. And . . . now.”

  A new speck, this one bright violet, materialized in the holo. Gathering speed, it recreated the 3-D shock wave.

  Jaime stood, squeezing behind his chair to study the image from another perspective. She poked a finger into the image. “Then whatever caused the waves is here?”

  “Obviously, the simulation runs faster than real-time. I’ve given you no way to gauge the compression factor. The object producing the wake is moving at one-tenth cee, and we’re nearly a light-year apart. To look at it, we aim”—Diego tweaked a program parameter, and a backward-extrapolated trajectory materialized—“where it was.”

  He linked their main telescope to the display. A dark sphere shimmered, faintly aglow in a false-color substitution for IR. Mountain peaks and hints of continental outlines peered out from beneath an all-encompassing blanket of ices.

  Sayeed leaned forward to read annotations floating above the globe. “An Earth-sized world. At one point, it was Earthlike, its oceans and atmosphere since frozen. It’s a bit warmer than the interstellar background, which is why we can detect it, perhaps leakage from a radioactive core. And somehow, you say, it’s racing by at one-tenth light speed. How can that be?”

  Barbara shook her head, setting her crest to bobbing. “A fair question, but I have a more basic one. Diego, you might have begun by showing us what you’d found. Why didn’t you?”

  “Because this isn’t about an out-of-place planet. I need you to accept the years of observation and the model that showed us where to look.” Diego took a deep breath. Would they believe? “They prove that that world has been accelerating steadily at 0.001 gee.

  “Someone is moving it—someone who controls techn
ology we can’t even imagine.”

  “ARE YOU AWAKE?”

  Diego was reasonably certain he’d been prodded in the ribs to assure a positive response. “Uh-huh,” he answered groggily. “What’s on your mind?”

  Propped up on an elbow, long hair looking stirred from tossing and turning, Jaime stared at him. “Are we doing the right thing?”

  For days, the four of them had gone around and around on this. Even Nguyen had come over. The big day was tomorrow.

  But decisions feel different in the dark. “Jeeves, lights to quarter bright,” he told the onboard computer. It had the good judgment to comply without speaking. “Hon, we’ve all agreed. We can’t let Earth decide! They’re almost fifteen light-years away. Whether they signal the aliens directly—which they wouldn’t, since there’s no guarantee the planet won’t change course in the meanwhile—or they tell us to proceed, that’d be nearly a thirty-year delay. What does that do for us?” Despite himself, a yawn interrupted his response.

  Then she surprised him. “That’s not what I meant. Maybe we shouldn’t contact them at all. What if they’re . . . hostile?”

  That brought him fully awake. Ascribing violent intent was a good way to get sent for medical help—but aboard this ship, she was the medical help. “Advanced civilizations are peaceful,” he said cautiously.

  “I know.” She raked a hand, fingers splayed, through her mussed hair. “War was a societal psychosis. With the resources of a solar system at our disposal, and with Fertility Boards to keep population levels under control, there’s been peace for more than a century. We left behind violence with the era of scarcity that the mentally ill used to excuse it.” The words came out like the secular catechism that they were. “They”—no antecedent was needed—“move entire worlds. How could they possibly covet the resources humans administer?”